Allocation and logical to physical mapping of scheduling request indicator channel in wireless networks

ABSTRACT

A method for allocating resources for a scheduling request indicator (SRI) is disclosed. An SRI cycle period for use by user equipment (UE) within a cell is transmitted from a NodeB in a cell to UE within the cell. The NodeB transmits a specific SRI subframe offset and an index value to the particular UE within the cell. The specific SRI subframe offset and the index value enable the UE to determine a unique combination of cyclic shift, RS orthogonal cover, data orthogonal cover, and resource block number for the UE to use as a unique physical resource for an SRI in the physical uplink control channel (PUCCH).

The present application discloses and claims only subject matterdisclosed in prior non-provisional application Ser. No. 13/245,994,filed Sep. 27, 2011, and names inventors named in the priornon-provisional application. Accordingly, this application mayconstitute a continuation or division;

Which is a continuation of prior application Ser. No. 12/344,156, filedDec. 24, 2008, now U.S. Pat. No. 8,059,524, granted Nov. 15, 2011;

Which claims priority to and incorporates by reference U.S. ProvisionalApplication No. 61/019,013, filed Jan. 4, 2008, entitled “Allocation andLogical to Physical Mapping of Scheduling Request Indicator Channel inWireless Networks.”

Which also claims priority to and incorporates by reference U.S.Provisional Application No. 61/023,225, filed Jan. 24, 2008, entitled“Allocation and Logical to Physical Mapping of Scheduling RequestIndicator Channel in Wireless Networks.”

Which also claims priority to and incorporates by reference U.S.Provisional Application No. 61/024,006, filed Jan. 28, 2008, entitled“Allocation and Logical to Physical Mapping of Scheduling RequestIndicator Channel in Wireless Networks.”

Which also claims priority to and incorporates by reference U.S.Provisional Application No. 61/032,519, filed Feb. 29, 2008, entitled“Allocation and Logical to Physical Mapping of Scheduling RequestIndicator Channel in Wireless Networks.”

FIELD OF THE INVENTION

This invention generally relates to wireless cellular communication, andin particular to transmission of scheduling request indicator signals inorthogonal frequency division multiple access (OFDMA), DFT-spread OFDMA,and single carrier frequency division multiple access (SC-FDMA) systems.

BACKGROUND OF THE INVENTION

Wireless cellular communication networks incorporate a number of mobileUEs and a number of NodeBs. A NodeB is generally a fixed station, andmay also be called a base transceiver system (BTS), an access point(AP), a base station (BS), or some other equivalent terminology. Asimprovements of networks are made, the NodeB functionality evolves, so aNodeB is sometimes also referred to as an evolved NodeB (eNB). Ingeneral, NodeB hardware, when deployed, is fixed and stationary, whilethe UE hardware is portable.

In contrast to NodeB, the mobile UE can comprise portable hardware. Userequipment (UE), also commonly referred to as a terminal or a mobilestation, may be fixed or mobile device and may be a wireless device, acellular phone, a personal digital assistant (PDA), a wireless modemcard, and so on. Uplink communication (UL) refers to a communicationfrom the mobile UE to the NodeB, whereas downlink (DL) refers tocommunication from the NodeB to the mobile UE. Each NodeB contains radiofrequency transmitter(s) and the receiver(s) used to communicatedirectly with the mobiles, which move freely around it. Similarly, eachmobile UE contains radio frequency transmitter(s) and the receiver(s)used to communicate directly with the NodeB. In cellular networks, themobiles cannot communicate directly with each other but have tocommunicate with the NodeB.

Long Term Evolution (LTE) wireless networks, also known as EvolvedUniversal Terrestrial Radio Access Network (E-UTRAN), are beingstandardized by the 3GPP working groups (WG). OFDMA and SC-FDMA (singlecarrier FDMA) access schemes were chosen for the down-link (DL) andup-link (UL) of E-UTRAN, respectively. User Equipments (UE's) are timeand frequency multiplexed on a physical uplink shared channel (PUSCH),and a fine time and frequency synchronization between UE's guaranteesoptimal intra-cell orthogonality. In case the UE is not UL synchronized,it uses a non-synchronized Physical Random Access Channel (PRACH), andthe Base Station (also referred to as NodeB) responds with allocated ULresource and timing advance information to allow the UE to transmit onthe PUSCH. The 3GPP RAN Working Group 1 (WG1) has agreed on a preamblebased physical structure for the PRACH. RAN WG1 also agreed on thenumber of available preambles that can be used concurrently to minimizethe collision probability between UEs accessing the PRACH in acontention-based manner. These preambles are multiplexed in CDM (codedivision multiplexing) and the sequences used are Constant AmplitudeZero Auto-Correlation (CAZAC) sequences. All preambles are generated bycyclic shifts of a number of root sequences, which are configurable on acell-basis.

In the case where the UE is UL synchronized, it uses a contention-freeScheduling Request (SR) channel for the transmission of a schedulingrequest. As opposed to the former case, the latter case is acontention-free access. In other words, a particular scheduling requestchannel in a particular transmission instance is allocated to at mostone UE. In 3GPP LTE, a two-state scheduling request indicator can betransmitted on a SR channel. In case a UE has a pending SR to transmit,it transmits a positive (or ON) SRI on its next available SR channel. Incase a UE does not have a pending SR to transmit, it transmits anegative (or OFF) SRI, or equivalently transmits nothing on its assignedSR channel. Such a “non-transmission” is also referred to as DTXtransmission. A pending (i.e. positive or ON) SRI is triggered by,including but are not limited to, buffer status changes orevent-triggered measurement reports. WG1 has agreed that a two-stateScheduling Request Indicator (SRI) be transmitted with On-Off Keyingusing a structure similar to ACK/NACK transmission.

Control information bits are transmitted, for example, in the uplink(UL), for several purposes. For instance, Downlink Hybrid AutomaticRepeat ReQuest (HARQ) requires at least one bit of ACK/NACK transmittedin the uplink, indicating successful or failed circular redundancycheck(s) (CRC). Moreover, a one-bit scheduling request indicator (SRI)is transmitted in uplink, when UE has new data arrival for transmissionin uplink. Furthermore, an indicator of downlink channel quality (CQI)needs to be transmitted in the uplink to support mobile UE scheduling inthe downlink. While CQI may be transmitted based on a periodic ortriggered mechanism, the ACK/NACK needs to be transmitted in a timelymanner to support the HARQ operation. Note that ACK/NACK is sometimesdenoted as ACKNAK or just simply ACK, or any other equivalent term. Asseen from this example, some elements of the control information shouldbe provided additional protection, when compared with other information.For instance, the ACK/NACK information is typically required to behighly reliable in order to support an appropriate and accurate HARQoperation. This uplink control information is typically transmittedusing a physical uplink control channel (PUCCH). The structure of thePUCCH is designed to provide sufficiently high transmission reliability.

In addition to PUCCH, the EUTRA standard also defines a physical uplinkshared channel (PUSCH), intended for transmission of uplink user data.The Physical Uplink Shared Channel (PUSCH) can be dynamically scheduled.This means that time-frequency resources of PUSCH are re-allocated everysub-frame. This (re)allocation is communicated to the mobile UE usingthe Physical Downlink Control Channel (PDCCH). Alternatively, resourcesof the PUSCH can be allocated semi-statically, via the mechanism ofsemi-persistent scheduling. Thus, any given time-frequency PUSCHresource can possibly be used by any mobile UE, depending on thescheduler allocation. The Physical Uplink Control Channel (PUCCH) isdifferent than the PUSCH, and the PUCCH is used for transmission ofuplink control information (UCI). Frequency resources which areallocated for PUCCH are found at the two extreme edges of the uplinkfrequency spectrum. In contrast, frequency resources which are used forPUSCH are in between. Since PUSCH is designed for transmission of userdata, re-transmissions are possible, and PUSCH is expected to begenerally scheduled with less stand-alone sub-frame reliability thanPUCCH. The general operations of the physical channels are described inthe EUTRA specifications, for example: “3^(rd) Generation PartnershipProject; Technical Specification Group Radio Access Network; EvolvedUniversal Terrestrial Radio Access (E-UTRA); Physical Channels andModulation (Release 8).”

A reference signal (RS) is a pre-defined signal, pre-known to bothtransmitter and receiver. The RS can generally be thought of asdeterministic from the perspective of both transmitter and receiver. TheRS is typically transmitted in order for the receiver to estimate thesignal propagation medium. This process is also known as “channelestimation.” Thus, an RS can be transmitted to facilitate channelestimation. Upon deriving channel estimates, these estimates are usedfor demodulation of transmitted information. This type of RS issometimes referred to as De-Modulation RS or DM RS. Note that RS canalso be transmitted for other purposes, such as channel sounding (SRS),synchronization, or any other purpose. Also note that Reference Signal(RS) can be sometimes called the pilot signal, or the training signal,or any other equivalent term.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular embodiments in accordance with the invention will now bedescribed, by way of example only, and with reference to theaccompanying drawings:

FIG. 1 is a pictorial of an illustrative telecommunications networkwhere SRI resources are allocated for transmission in uplink accordingto an embodiment of the present invention;

FIG. 2 is a ladder diagram illustrating a Scheduling Request procedurefor UL synchronized UEs using an allocated SRI resource in the networkof FIG. 1;

FIGS. 3 and 4 illustrate SRI transmission structures per slot on PUCCHfor short and long CP, respectively, for use in the network of FIG. 1;

FIG. 5 is a frequency/time plot illustrating PUCCH and PUSCH,illustrating exemplary SRI resource time indexing per RB;

FIG. 6 is a frequency/time plot illustrating PUCCH and PUSCH,illustrating exemplary resource block indexing;

FIG. 7 is a flow diagram illustrating allocation and transmission of SRIaccording to an embodiment of the present invention;

FIG. 8 is a block diagram of a transmitter structure for transmittingthe SRI structures of FIGS. 3-4;

FIG. 9 is an exemplary block diagram of a Node B and a User Equipmentfor use in the network system of FIG. 1; and

FIG. 10 is a block diagram of a cellular phone for use in the network ofFIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The SRI (schedule request indicator) is configured semi-statically bythe eNB, and occurs periodically. The typical period for the SRI is 10ms so as to provide a low-latency procedure whenever the UE needs totransmit new data. A simple method for provisioning and allocating SRIresources on PUCCH is described herein, summarized as follows. First, aone-to-one mapping of logical SRI index to physical resources is definedfor all PUCCH RBs. Then, the eNB signals the start and period of the SRIcycle, and allocates an SRI resource index to a UE through L3 signaling.

FIG. 1 shows an exemplary wireless telecommunications network 100. Theillustrative telecommunications network includes representative basestations 101, 102, and 103; however, a telecommunications networknecessarily includes many more base stations. Each of base stations 101,102, and 103 are operable over corresponding coverage areas 104, 105,and 106. Each base station's coverage area is further divided intocells. In the illustrated network, each base station's coverage area isdivided into three cells. Handset or other UE 109 is shown in Cell A108, which is within coverage area 104 of base station (eNB) 101. Basestation 101 is transmitting to and receiving transmissions from UE 109via downlink 110 and uplink 111. A UE in a cell may be stationary suchas within a home or office, or may be moving while a user is walking orriding in a vehicle. UE 109 moves within cell 108 with a velocity 112relative to base station 101. As UE 109 moves out of Cell A 108, andinto Cell B 107, UE 109 may be handed over to base station 102. BecauseUE 109 is synchronized with base station 101, UE 109 must employnon-synchronized random access to initiate handover to base station 102.As long as UE remains within cell 108 and remains synchronized to eNB101 it may request allocation of resources using the scheduling requestprocedure. The particular resource used by UE 109 to transmit SRI isallocated to it by eNB 101, using a allocation procedure that will bedescribed in more detail below. As UE 109 moves from coverage area 104to coverage area 105 that is controlled by eNB 102 it will receive a newSRI allocation from eNB 102 using the allocation procedure after itbecomes synchronized with eNB 102.

FIG. 2 is a ladder diagram illustrating a scheduling request procedurefor UL synchronized UEs. For example, a UE, such as UE 109 in FIG. 1, issemi-statically allocated an SRI channel on a set of periodictransmission instances using the allocation procedure that will bedescribed in more detail below. When UE 109 determines that it needs totransmit data or information to eNB 101 (i.e. the UE has a pendingscheduling request), it first transmits a positive (or ON) SRI 202 atits next assigned SRI transmission opportunity. Here, an SRItransmission opportunity refers to an allocated SRI channel on atransmission instance. The eNB receives SRI 202 and then issues anuplink scheduling grant 204 to UE 108. UE 108 then transmits ascheduling request (SR) 206 along with data defining what resources arerequired using the just-allocated resource indicated in scheduling grant204.

FIGS. 3 and 4 illustrate coherent orthogonal structures 300 and 400,respectively, which support transmission of SRI by multiple users withinthe same frequency and time resource. A similar structure is specifiedin E-UTRA specifications for ACK/NACK transmission on PUCCH. FIG. 3illustrates one slot 300 of a transmission frame in which normal cyclicprefix (CP) are used, where C₀-C₁₁ represent the cyclic shifts of a rootCAZAC-like sequence, and S₀-S₆ represent seven OFDM symbols per slot(0.5 ms). Without loss of generality, the middle three OFDM symbolsS₂-S₄ carry PUCCH DM RS, while the other four OFDM symbols carry SRIdata information. Orthogonal covering 302 and 304 is applied to the databearing OFDM symbols and the RS OFDM symbols, respectively. A thirdlength-2 orthogonal covering sequence 306 is applied on to the length-3and length-4 orthogonal covering sequences. In case a UE has a pendingscheduling request and is transmitting a positive (or ON) SRI, then theCAZAC-like sequences in OFDM symbols S₀, S₁, S₅, S₆ aremodulated/multiplied by 1. In case a UE does not have a pendingscheduling requesting, it does not transmit any signal on its assignedSRI channel, including the RS symbols and the data symbols, which isequivalent to transmitting a negative (or OFF) SRI.

Similarly, FIG. 4 illustrates one slot 400 of a transmission frame inwhich extended cyclic prefix (CP) are used and therefore only sixsymbols S₀-S₅ are available per slot (0.5 ms). The middle two OFDMsymbols S₂-S₃ carry PUCCH DM RS, while the other four OFDM symbols carrySRI data information. Orthogonal covering 402 and 404 is applied to thedata bearing OFDM symbols and the RS OFDM symbols, respectively. A thirdlength-2 orthogonal covering sequence 406 is applied on to the length-2orthogonal covering sequence 404 and length-4 orthogonal coveringsequence 402. In case a UE has a pending scheduling request and istransmitting a positive (or ON) SRI, then the CAZAC-like sequences inOFDM symbols S₀, S₁, S₄, S₅ are modulated/multiplied by 1. In case a UEdoes not have a pending scheduling requesting, it does not transmit anysignal on its assigned SRI channel, including the RS symbols and thedata symbols, which is equivalent to transmit a negative (or OFF) SRI.

For the SRI structure illustrated in FIG. 3, in each slot of a two slotsub-frame, a seven symbol length sequence is split into two orthogonalsequences, length three and length four, as illustrated. In 3GPP LTE,the defined length-3 orthogonal covering sequence 304 is a DFT sequence,while the length-4 orthogonal covering sequence 302 is a Hadamardsequence. A third length-2 orthogonal covering sequence 306 can beapplied on to the length-3 and length-4 orthogonal covering sequences,which allows multiplexing up to six UEs per cyclic shift. Using up tosix cyclic shifts out of twelve available per 180 kHz frequency resourceblock (RB) this SRI channel can multiplex 36 UEs per RB and persub-frame (1 ms). Given a desired SRI period of 10 ms per UE, andassuming SRI channels are continuously allocated along one RB, the SRcapacity is 360 UEs per RB, which is in-line with the estimated numberof UL synchronized UEs in 5 MHz. A similar reasoning yields 240 UEs perRB with the long CP structure, as illustrated in FIG. 4. Similar toACK/NACK and CQI, slot hopping within a sub-frame is enabled across thetwo PUCCH regions at both UL system bandwidth edges.

In case the third length-2 orthogonal covering is not used to allowACK/NACK and SRI sharing a common allocation scheme, the SRI capacity isreduced to the ACK/NACK capacity: 18 UEs per RB with normal cyclicprefix and 12 UEs per RB with extended cyclic prefix.

In another embodiment, C₀-C₁₁ represent 12 different amounts of phaseramp applied to a root CAZAC-like sequence. A cyclic shifted sequence isobtained by a cyclic shift operation on the root sequence, which istypically defined in the time domain. Phase ramped sequence is obtainedby a phase ramp operation on the root sequences, which is typicallydefined in the frequency domain. The proposed method in this disclosureapplies to both cyclic shifted sequences and phase ramped sequences.

In each OFDM symbol, a cyclically shifted or phase ramped CAZAC-likesequence is transmitted. The CAZAC-like sequence in an PUCCH DM RS OFDMsymbol is un-modulated, or equivalently modulated/multiplied by 1. TheCAZAC-like sequence in a data OFDM symbol is modulated by the datasymbol. In case of a positive SRI transmission, the CAZAC-like sequencein a data OFDM symbol is modulated/multiplied by 1. In this disclosure,a CAZAC-like sequence generally refers to any sequence that has theproperty of constant amplitude zero auto correlation. Examples ofCAZAC-like sequences includes but not limited to, Chu Sequences,Frank-Zadoff Sequences, Zadoff-Chu (ZC) Sequences, GeneralizedChirp-Like (GCL) Sequences, or any computer generated CAZAC sequences.One example of a CAZAC-like sequence r _(u,v)(n) is given byr _(u,v)(n)=e ^(jφ(n)π/4), 0≦n≦M _(sc) ^(RS)−1

where M_(sc) ^(RS)=12 and φ(n) is defined in Table 1.

In this disclosure, the cyclically shifted or phase ramped CAZAC-likesequence is sometimes denoted as cyclic shifted base sequence, cyclicshifted root sequence, phase ramped base sequence, phase ramped rootsequence, or any other equivalent term.

TABLE 1 Definition of φ(n) u φ(0), . . . , φ(11) 0 −1 1 3 −3 3 3 1 1 3 1−3 3 1 1 1 3 3 3 −1 1 −3 −3 1 −3 3 2 1 1 −3 −3 −3 −1 −3 −3 1 −3 1 −1 3−1 1 1 1 1 −1 −3 −3 1 −3 3 −1 4 −1 3 1 −1 1 −1 −3 −1 1 −1 1 3 5 1 −3 3−1 −1 1 1 −1 −1 3 −3 1 6 −1 3 −3 −3 −3 3 1 −1 3 3 −3 1 7 −3 −1 −1 −1 1−3 3 −1 1 −3 3 1 8 1 −3 3 1 −1 −1 −1 1 1 3 −1 1 9 1 −3 −1 3 3 −1 −3 1 11 1 1 10 −1 3 −1 1 1 −3 −3 −1 −3 −3 3 −1 11 3 1 −1 −1 3 3 −3 1 3 1 3 312 1 −3 1 1 −3 1 1 1 −3 −3 −3 1 13 3 3 −3 3 −3 1 1 3 −1 −3 3 3 14 −3 1−1 −3 −1 3 1 3 3 3 −1 1 15 3 −1 1 −3 −1 −1 1 1 3 1 −1 −3 16 1 3 1 −1 1 33 3 −1 −1 3 −1 17 −3 1 1 3 −3 3 −3 −3 3 1 3 −1 18 −3 3 1 1 −3 1 −3 −3 −1−1 1 −3 19 −1 3 1 3 1 −1 −1 3 −3 −1 −3 −1 20 −1 −3 1 1 1 1 3 1 −1 1 −3−1 21 −1 3 −1 1 −3 −3 −3 −3 −3 1 −1 −3 22 1 1 −3 −3 −3 −3 −1 3 −3 1 −3 323 1 1 −1 −3 −1 −3 1 −1 1 3 −1 1 24 1 1 3 1 3 3 −1 1 −1 −3 −3 1 25 1 −33 3 1 3 3 1 −3 −1 −1 3 26 1 3 −3 −3 3 −3 1 −1 −1 3 −1 −3 27 −3 −1 −3 −1−3 3 1 −1 1 3 −3 −3 28 −1 3 −3 3 −1 3 3 −3 3 3 −1 −1 29 3 −3 −3 −1 −1 −3−1 3 −3 3 1 −1

FIG. 5 is frequency vs. time plot illustrating PUSCH 502 and PUCCH 504,505, with Scheduling Request Indicators transmitted in the PUCCH. Inthis patent application, without loss of generality, an SRI is sent onthe PUCCH, as described with respect to FIGS. 3 and 4. As mentionedearlier, SRI is continuously allocated on one RB of the physical uplinkcontrol channel (PUCCH) such that thirty-six UEs can be multiplexed inone RB subframe, as indicated generally at 507. The next sequentialsubframe is indicated at 509 and can likewise support up to thirty-sixUE. Within a sub-frame, the SRI hops at both edges of the systembandwidth on a slot basis. Each slot represents one-half of a subframe.For example, an SRI in slot 506-1 of subframe 507 is in the higherfrequency edge 504 and the SRI is repeated in slot 506-2 of subframe 507which is in the lower frequency edge 505 of the PUCCH. Similarly, slots508-1, 508-2 carry SRI for the next set of thirty-six UE in subframe509. In general, the first and second slot SRI sequences are the same,but they may be different in some embodiments.

One-to One SRI Resource Mapping

As indicated above, embodiments of the present invention provide asimple method for provisioning and allocating SRI resources on PUCCH, byforming a one-to-one mapping of a logical SRI index to physicalresources, defined for all PUCCH RBs, as will now be described in moredetail. The eNB may then signal the start and period of the SRI cycle,and allocate an SRI resource index to a UE through L3 signaling.

The following descriptions cover a cyclic shift separation of twobetween resources using the same orthogonal covering code, defined as:Δ_(shift) ^(PUCCH)=2

A cyclic shift of two is expected to be the most common allocation. Thefollowing descriptions also cover cyclic shift separations of one andthree. It is to be understood that other embodiments of the inventionmay use cyclic shift separation of four or larger using the principlesdescribed herein.

Embodiments of the invention use a fixed and simple SRI resourceindexing based on a channelization structure and indexing at thesubframe/RB level, followed by a time first, frequency (RB) 2nd orderingscheme, as elaborated in the following sections.

SRI Resource Indexing for the Sub-frame/RB Level—Short CP

Referring again to FIG. 3, the set of orthogonal covering sequences 302,304, 306 is defined as follows in 3GPP TS 36.211 V8.4.0 (2008-09)“Technical Specification Group Radio Access Network; Evolved UniversalTerrestrial Radio Access (E-UTRA); Physical Channels and Modulation(Release 8)” Tables 5.4.1-2, 5.4.1-3 and 5.5.2.2.1-2:

Block spreading 1 (302): {c1,1, c1,2, c1,3} chosen from {(1,1,1,1),(1,1,−1,−1), (1,−1,−1,1), (1,−1,1,−1)}

Block spreading 2 (304): {c2,1, c2,2, c2,3}={(1,1,1), (1,exp(j2pi/3),exp(j4pi/3)), (1, exp(j4pi/3), exp(j8pi/3))}

Block spreading 3 (306): {c3,1, c3,2}={(1,1), (1,−1)}

Block spreading sequence 1 is summarized in Table 2. In a similar manneras used for the ACK/NACK channelization structure, only three out of thefour sequences are used at a time for block spreading 1. Therefore,subsets of three sequences are defined to minimize the interference inhigh speed as illustrated in Table 2.

TABLE 2 Orthogonal code subsets for block spreading sequence 1 Set index(Si) c_(1, 1) c_(1, 2) c_(1, 3) #1 (1, 1, 1, 1) (1, −1, 1, −1) (1, −1,−1, 1) #2 (1, 1, −1, −1) (1, −1, −1, 1) (1, −1, 1, −1) #3 (1, −1, −1, 1)(1, 1, −1, −1) (1, 1, 1, 1) #4 (1, −1, 1, −1) (1, 1, 1, 1) (1, 1, −1,−1)

The various possible code sets can be used alternately, so as to providesome interference randomization (slot-level orthogonal cover hopping).In addition, a staggered cyclic shift allocation should be used, wherethe most interfering code is allocated to an adjacent cyclic shift, asshown in Table 3. The different cyclic shift indexes (Si) reflectdifferent possible alternate mappings, offset by one cyclic shift. Thefollowing sub-sections define channelization structures and resultingSRI resource indexing for the cases where a cyclic shift separation ofone, two and three cyclic shifts is assumed between resources using thesame orthogonal covering code.

A cyclic shift separation of two is expected to be the broaderconfiguration usage and corresponds to most urban and sub-urban celldeployment scenarios. In this configuration, the SRI multiplexingcapacity in one subframe/RB is:N_(SRI) ^(SFRB)=36

TABLE 3 Staggered cyclic shift allocation structure for block spreading1&2, for Short CP and shift separation equal 2 Block spreading Blockspreading code 1 Cyclic shift code 2 c_(1, 1) c_(1, 2) c_(1, 3) Index 1Index 2 c_(2, 1) c_(2, 2) c_(2, 3) of Si of Si of Si 0 1 ✓ ✓ ✓ ✓ 1 2 ✓ ✓2 3 ✓ ✓ ✓ ✓ 3 4 ✓ ✓ 4 5 ✓ ✓ ✓ ✓ 5 6 ✓ ✓ 6 7 ✓ ✓ ✓ ✓ 7 8 ✓ ✓ 8 9 ✓ ✓ ✓ ✓9 10 ✓ ✓ 10 11 ✓ ✓ ✓ ✓ 11 0 ✓ ✓

Using the spreading codes as defined in Table 2 and Table 3, anembodiment of the present invention may use the RB/sub-frame level SRIresource indexing as described in Table 4

TABLE 4 RB/sub-frame level SRI channel indexing - Short CP Blockspreading Block Block spreading code 1 spreading Cyclic shift code 2 c1,1 c1, 2 c1, 3 code 3 Index 1 Index 2 c2, 1 c2, 2 c2, 3 of Si of Si of Sic3, 1 0 1 0 12 0 12 1 2 6 6 2 3 1 13 1 13 3 4 7 7 4 5 2 14 2 14 5 6 8 86 7 3 15 3 15 7 8 9 9 8 9 4 16 4 16 9 10 10 10 10 11 5 17 5 17 11 0 1111 c3, 2 0 1 18 30 18 30 1 2 24 24 2 3 19 31 19 31 3 4 25 25 4 5 20 3220 32 5 6 26 26 6 7 21 33 21 33 7 8 27 27 8 9 22 34 22 34 9 10 28 28 1011 23 35 23 35 11 0 29 29

A cyclic shift separation of three is expected to be used in cells withlarge delay spread (for example, some specific rural areas) but where ashort CP is used. In this configuration, the SRI multiplexing capacityin one subframe/RB isN_(SRI) ^(SFRB)=24

Table 5 illustrates a staggered cyclic shift allocation structure forblock spreading sequence 1 and 2 for the short CP structure of FIG. 3,where the cyclic shift separation is three. As mentioned earlier, themultiple columns of cyclic shift indexes address different origins (oroffsets) used to implement the cyclic shifts. For example, with a cyclicshift increment of 3, cyclic shifts of 0, 3, 6, . . . or 1, 4, 7, . . .or 2, 5, 8, . . . etc may be implemented.

TABLE 5 Staggered cyclic shift allocation structure for block spreading1&2 - for Short CP and cyclic shift separation equal 3 Block spreadingBlock spreading code 1 Cyclic shift code 2 c_(1, 1) c_(1, 2) c_(1, 3)Index 1 Index 2 Index 3 c_(2, 1) c_(2, 2) c_(2, 3) of Si of Si of Si 0 12 ✓ ✓ 1 2 3 ✓ ✓ 2 3 4 ✓ ✓ 3 4 5 ✓ ✓ 4 5 6 ✓ ✓ 5 6 7 ✓ ✓ 6 7 8 ✓ ✓ 7 8 9✓ ✓ 8 9 10 ✓ ✓ 9 10 11 ✓ ✓ 10 11 0 ✓ ✓ 11 0 1 ✓ ✓

Using the spreading codes as defined in Table 5 for a shift separationof three, an embodiment of the present invention may use theRB/sub-frame level SRI resource indexing as described in Table 6

TABLE 6 RB/sub-frame level SRI channel indexing, for short CP and shiftseparation = 3 Block spreading Block Block spreading code 1 spreadingCyclic shift code 2 c1, 1 c1, 2 c1, 3 code 3 Index 1 Index 2 Index 3 c2,1 c2, 2 c2, 3 of Si of Si of Si c3, 1 0 1 2 0 0 1 2 3 4 4 2 3 4 8 8 3 45 1 1 4 5 6 5 5 5 6 7 9 9 6 7 8 2 2 7 8 9 6 6 8 9 10 10 10 9 10 11 3 310 11 0 7 7 11 0 1 11 11 c3, 2 0 1 2 12 12 1 2 3 16 16 2 3 4 20 20 3 4 513 13 4 5 6 17 17 5 6 7 21 21 6 7 8 14 14 7 8 9 18 18 8 9 10 22 22 9 1011 15 15 10 11 0 19 19 11 0 1 23 23

A cyclic shift separation of one is expected to be used in cells with asmall delay spread, in which case the SRI multiplexing capacity can beincreased to 72 SRIs in one subframe/RB, such that:N_(SRI) ^(SFRB)=72

Table 7 illustrates a staggered cyclic shift allocation structure forblock spreading sequence 1 and 2 for the short CP structure of FIG. 3,where the cyclic shift separation is one.

TABLE 7 Staggered cyclic shift allocation structure for block spreading1&2, for short CP and cyclic shift separation equal one Cyclic Blockspreading code 1 shift Block spreading code 2 c1, 1 c1, 2 c1, 3 indexc2, 1 c2, 2 c2, 3 of Si of Si of Si 0 ✓ ✓ ✓ ✓ ✓ ✓ 1 ✓ ✓ ✓ ✓ ✓ ✓ 2 ✓ ✓ ✓✓ ✓ ✓ 3 ✓ ✓ ✓ ✓ ✓ ✓ 4 ✓ ✓ ✓ ✓ ✓ ✓ 5 ✓ ✓ ✓ ✓ ✓ ✓ 6 ✓ ✓ ✓ ✓ ✓ ✓ 7 ✓ ✓ ✓ ✓✓ ✓ 8 ✓ ✓ ✓ ✓ ✓ ✓ 9 ✓ ✓ ✓ ✓ ✓ ✓ 10 ✓ ✓ ✓ ✓ ✓ ✓ 11 ✓ ✓ ✓ ✓ ✓ ✓

Using the spreading codes as defined in Table 7 for a shift separationof one, an embodiment of the present invention may use the RB/sub-framelevel SRI resource indexing as described in Table 8.

TABLE 8 RB/sub-frame level SRI channel indexing, for short CP and shiftseparation = 1 Block Cyclic Block spreading code 1 spreading shift Blockspreading code 2 c_(1, 1) c_(1, 2) c_(1, 3) code 3 index c_(2, 1)c_(2, 2) c_(2, 3) of Si of Si of Si c_(3, 1) 0 0 12 24 0 12 24 1 1 13 251 13 25 2 2 14 26 2 14 26 3 3 15 27 3 15 27 4 4 16 28 4 16 28 5 5 17 295 17 29 6 6 18 30 6 18 30 7 7 19 31 7 19 31 8 8 20 32 8 20 32 9 9 21 339 21 33 10 10 22 34 10 22 34 11 11 23 35 11 23 35 c_(3, 2) 0 36 48 60 3648 60 1 37 49 61 37 49 61 2 38 50 62 38 50 62 3 39 51 63 39 51 63 4 4052 64 40 52 64 5 41 53 65 41 53 65 6 42 54 66 42 54 66 7 43 55 67 43 5567 8 44 56 68 44 56 68 9 45 57 69 45 57 69 10 46 58 70 46 58 70 11 47 5971 47 59 71SRI Resource Indexing for Sub-Frame/RB Level—Long CP

For the long CP structure of FIG. 4, a set of orthogonal coveringsequences is defined as follows by 3GPP TS 36.211 V8.4.0 (2008-09)Tables 5.4.1-2, 5.4.1-3 and 5.5.2.2.1-2:

-   -   Block spreading 1: {c_(1,1), c_(1,2)} chosen from {(1,1,1,1),        (1,1,−1,−1), (1,−1,−1,1), (1,−1,1,−1)}(see Table 9 below)    -   Block spreading 2: {c_(2,1), c_(2,2)}={(1,1), (1,−1)}    -   Block spreading 3: {c_(3,1), c_(3,2)}={(1,1), (1,−1)}

Two out of the four sequences are used at a time for block spreadingsequence 1. Therefore, it is possible to always select the optimalsequences which remain orthogonal even at high speed, as shown in Table9.

TABLE 9 Orthogonal code subsets for block spreading sequence 1 Set index(Si) c_(1, 1) c_(1, 2) #1 (1, 1, 1, 1) (1, −1, −1, 1) #2 (1, 1, −1, −1)(1, −1, 1, −1) #3 (1, −1, −1, 1) (1, 1, 1, 1) #4 (1, −1, 1, −1) (1, 1,−1, −1)

A cyclic shift separation of two is expected to be the broaderconfiguration usage and corresponds to most urban and sub-urban celldeployment scenarios. In this configuration, the SRI multiplexingcapacity in one subframe/RB is 24. Given the good performance of theabove codes, there is no such need to introduce a staggered structure,as for the short CP case. Therefore, the two possible channelizationstructures are given in Table 10 (non-staggered) and Table 11(staggered).

TABLE 10 Cyclic shift allocation structure for block spreading 1&2, Nonstaggered, Long CP, shift separation = 2 Cyclic shift Block spreadingcode 2 Block spreading code 1 Index1 Index 2 c_(2, 1) c_(2, 2) c_(1, 1)of Si c_(1, 2) of Si 0 1 ✓ ✓ ✓ ✓ 1 2 2 3 ✓ ✓ ✓ ✓ 3 4 4 5 ✓ ✓ ✓ ✓ 5 6 6 7✓ ✓ ✓ ✓ 7 8 8 9 ✓ ✓ ✓ ✓ 9 10 10 11 ✓ ✓ ✓ ✓ 11 0

TABLE 11 Cyclic shift allocation structure for block spreading 1&2,Staggered, Long CP, shift separation = 2 Cyclic shift Block spreadingcode 2 Block spreading code 1 Index1 Index 2 c_(2, 1) c_(2, 2) c_(1, 1)of Si c_(1, 2) of Si 0 1 ✓ ✓ 1 2 ✓ ✓ 2 3 ✓ ✓ 3 4 ✓ ✓ 4 5 ✓ ✓ 5 6 ✓ ✓ 6 7✓ ✓ 7 8 ✓ ✓ 8 9 ✓ ✓ 9 10 ✓ ✓ 10 11 ✓ ✓ 11 0 ✓ ✓

An embodiment of the present invention may use the RB/sub-frame levelSRI resource indexing as described in Table 12 where indexes formattedas (i) apply to the staggered structure in Table 11.

TABLE 12 RB/sub-frame level SRI channel indexing, Long CP, shiftseparation = 2 Block spreading Block Block spreading code 1 spreadingCyclic shift code 2 c1, 1 c1, 2 code 3 Index 1 Index 2 c2, 1 c2, 2 of Siof Si c3, 1 0 1 0  6 0  6 1 2  (6)  (6) 2 3 1  7 1  7 3 4  (7)  (7) 4 52  8 2  8 5 6  (8)  (8) 6 7 3  9 3  9 7 8  (9)  (9) 8 9 4 10 4 10 9 10(10) (10) 10 11 5 11 5 11 11 0 (11) (11) c3, 2 0 1 12 18 12 18 1 2 (18)(18) 2 3 13 19 13 19 3 4 (19) (19) 4 5 14 20 14 20 5 6 (20) (20) 6 7 1521 15 21 7 8 (21) (21) 8 9 16 22 16 22 9 10 (22) (22) 10 11 17 23 17 2311 0 (23) (23)

A cyclic shift separation of three is expected to be used in cells withlarge delay spread (e.g. some specific rural areas). In thisconfiguration, the SRI multiplexing capacity in one subframe/RB isN_(SRI) ^(SFRB)=16

Table 13 illustrates a staggered cyclic shift allocation structure forblock spreading sequence 1 and 2 for the long CP structure of FIG. 4,where the cyclic shift separation is three.

TABLE 13 Cyclic shift allocation structure for block spreading 1&2,Staggered, Long CP, shift separation = 3 Block spreading Block spreadingcode 1 Cyclic shift code 2 c_(1, 1) c_(1, 2) Index 1 Index 2 Index 3c_(2, 1) c_(2, 2) of Si of Si 0 1 2 ✓ ✓ 1 2 3 ✓ ✓ 2 3 4 3 4 5 ✓ ✓ 4 5 6✓ ✓ 5 6 7 6 7 8 ✓ ✓ 7 8 9 ✓ ✓ 8 9 10 9 10 11 ✓ ✓ 10 11 0 ✓ ✓ 11 0 1

Using the spreading codes as defined in Table 13 for a shift separationof three, an embodiment of the present invention may use theRB/sub-frame level SRI resource indexing as described in Table 14

TABLE 14 RB/sub-frame level SRI channel indexing, Long CP, shiftseparation = 3 Block spreading Block Cyclic shift Block spreading code 1spreading Index Index Index code 2 c1, 1 c1, 2 code 3 1 2 3 c2, 1 c2, 2of Si of Si c3, 1 0 1 2 0 0 1 2 3 4 4 2 3 4 3 4 5 1 1 4 5 6 5 5 5 6 7 67 8 2 2 7 8 9 6 6 8 9 10 9 10 11 3 3 10 11 0 7 7 11 0 1 c3, 2 0 1 2 8 81 2 3 12 12 2 3 4 3 4 5 9 9 4 5 6 13 13 5 6 7 6 7 8 10 10 7 8 9 14 14 89 10 9 10 11 11 11 10 11 0 15 15 11 0 1

In case the third length-2 orthogonal covering is not used to allowACK/NACK and SRI sharing a common allocation scheme, the above Tables 4,6, 8, 12, and 14 reduce to their upper part where only channelizationcode c_(3,1) is used.

Channelization Formulas and Sequence/Cyclic Shift Hopping

The above Tables 4, 6, 8, 12, and 14 can be used to identify thechannelization resource uniformly across all SC-OFDM symbols of one 1 mssubframe. Another possibility is that resource re-mapping is enabled ata symbol level for the cyclic shift resource and at a slot level for theorthogonal covering resource within the RB/subframe according to acell-specific or resource specific hopping pattern or a mix of both. Thepurpose of intra subframe resource hopping is to randomize the intra andinter-cell interference. In that case, the above tables define thechannelization resource of the first symbol of the subframe, providedresource hopping is enabled across following symbols within thechannelization framework defined by the above tables. This can becaptured analytically as described in the following paragraphs.

Let N_(SC) ^(RB)=12 be the number of sub-carriers in one resource block(RB) and, as a consequence, the maximum number of cyclic shifts per RB.As defined in the above sections, Δ_(shift) ^(PUCCH) is the cyclic shiftseparation between resources using the same orthogonal covering code andN_(SRI) ^(SFRB) is the SRI multiplexing capacity in one subframe/RB,given Δ_(shift) ^(PUCCH). Let n_(SRI) denote the SRI channel (orresource) index, where n_(SRI) is non-negative integer such that

$\begin{matrix}{{0 \leq n_{SRI} < N_{SRI}^{SFRB}},{{and}\mspace{14mu}{where}}} & \; \\{N_{SRI}^{SFRB} = \left\{ \begin{matrix}{6{N_{SC}^{RB}/\Delta_{shift}^{PUCCH}}} & {{for}\mspace{14mu}{normal}\mspace{14mu}{cyclic}\mspace{14mu}{prefix}} \\{4{N_{SC}^{RB}/\Delta_{shift}^{PUCCH}}} & {{for}\mspace{14mu}{extended}\mspace{14mu}{cyclic}\mspace{14mu}{prefix}}\end{matrix} \right.} & (7)\end{matrix}$

-   -   Denote n_(OC,1) ^((n) ^(s) ⁾ a non-negative integer such that        0≦n_(OC,1) ^((n) ^(s) ⁾<3; indexing the sequence

c_(1, (n_(OC, 1)^((n_(s))) + 1))

-   -    of “block spreading code 1” defined by (1), to be used in slot        n_(s) of the subframe.    -   Denote n_(OC,2) ^((n) ^(s) ⁾ a non-negative integer such that        0≦n_(OC,2) ^((n) ^(s) ⁾<3; indexing the sequence

c_(1, (n_(OC, 2)^((n_(s))) + 1))

-   -    of “block spreading code 2” defined by (2), to be used in slot        n_(s) of the subframe.    -   Denote n_(OC,3) ^((n) ^(s) ⁾ a non-negative integer such that        0≦n_(OC,3) ^((n) ^(s) ⁾<2; indexing the sequence

c_(1, (n_(OC, 3)^((n_(s))) + 1))

-   -    of “block spreading code 3” defined in (3), to be used in slot        n_(s) of the subframe.

Resources used for SRI transmission on PUCCH are identified by theresource index n_(SRI) from which the orthogonal sequence indexesn_(OC,1) ^((n) ^(s) ⁾,n_(OC,2) ^((n) ^(s) ⁾,n_(OC,3) ^((n) ^(s) ⁾,and the cyclic shift α(l) are determined according to:n _(OC,1) ^((n) ^(s) ⁾=(n _(OC,1) ⁽⁰⁾ +f ₁(n _(s)))mod 3  (8)n _(OC,2) ^((n) ^(s) ⁾=(n _(OC,2) ⁽⁰⁾ +f ₂(n _(s)))mod 3  (9)n _(OC,3) ^((n) ^(s) ⁾=(n _(OC,3) ⁽⁰⁾ +f ₃(n _(s)))mod 3  (10)α(l)=(α⁽⁰⁾+ƒ₄(l))mod N _(SC) ^(RB)  (11)where

$\begin{matrix}{n_{{OC},1}^{(0)} = \left\{ \begin{matrix}\left\lfloor {\left( {n_{SRI}{{mod}\left( {N_{SRI}^{SFRB}/2} \right)}} \right){\Delta_{shift}^{PUCCH}/N_{SC}^{RB}}} \right\rfloor & {{for}\mspace{14mu}{normal}\mspace{14mu}{cyclic}\mspace{14mu}{prefix}} \\{2\left\lfloor {\left( {n_{SRI}{{mod}\left( {N_{SRI}^{SFRB}/2} \right)}} \right){\Delta_{shift}^{PUCCH}/N_{SC}^{RB}}} \right\rfloor} & {{for}\mspace{14mu}{extended}\mspace{14mu}{cyclic}\mspace{14mu}{prefix}}\end{matrix} \right.} & (12) \\{\mspace{79mu}{n_{{OC},2}^{(0)} = \left\lfloor {\left( {n_{SRI}{{mod}\left( {N_{SRI}^{SFRB}/2} \right)}} \right){\Delta_{shift}^{PUCCH}/N_{SC}^{RB}}} \right\rfloor}} & (13) \\{\mspace{79mu}{n_{{OC},3}^{(0)} = \left\lfloor {2{n_{SRI}/N_{SRI}^{SFRB}}} \right\rfloor}} & (14) \\{\alpha^{(0)} = \left\{ \begin{matrix}\begin{pmatrix}{{\left( {n_{SRI}{{mod}\left( \frac{N_{SRI}^{SFRB}}{2} \right)}} \right)\Delta_{shift}^{PUCCH}} + \delta_{offset}^{PUCCH} +} \\\left( {n_{{OC},1}^{(0)}{mod}\;\Delta_{shift}^{PUCCH}} \right)\end{pmatrix} & {{mod}\; N_{SC}^{RB}\mspace{14mu}{normal}\mspace{11mu}{cp}} \\\begin{pmatrix}{{\left( {n_{SRI}{{mod}\left( \frac{N_{SRI}^{SFRB}}{2} \right)}} \right)\Delta_{shift}^{PUCCH}} + \delta_{offset}^{PUCCH} +} \\n_{{OC},2}^{(0)}\end{pmatrix} & {{mod}\; N_{SC}^{RB}\mspace{14mu}{extended}\mspace{11mu}{cp}}\end{matrix} \right.} & (15)\end{matrix}$

and f₁(n_(s)), f₂(n_(s)), f₃(n_(s)) represent index hopping functionsvarying per slot and f₄(I) represents index hopping function varying persymbol.

It should be noted that if orthogonal cover hopping is applied to bothn_(OC,1) ^((n) ^(s) ⁾ and n_(OC,2) ^((n) ^(s) ⁾

through hopping functions f₁(n_(s)) and f₂(n_(s)), then any additionalhopping on top will not improve the performance significantly so thatthe most likely hopping function forn_(OC,3) ^((n) ^(s) ⁾ is f3(ns)=0.RB Level

For a given RB, the number of time-multiplexed UEs is limited by the SRIperiod, which is generally set to 10 ms. Therefore, embodiments of theinvention pursue the SRI channel indexing beyond the sub-frame levelover an entire SRI period. Given the SRI period N_(SRI) expressed innumber subframes (e.g. N_(SRI)=10), the SRI channel index startsincrementing within the same RB from the first subframe of the SRIperiod until the last subframe of the SRI period. Formally, if S0 is thenumber of the first subframe of an SRI period, the SRI resource indexedby n is located in subframeS0+└n/N_(SRI) ^(SFRB)┘

on the channelization resource indexed by (n mod N_(SRI) ^(SFRB)) inTable 4, 6, 8, 12, 14. N_(SRI) ^(SFRB) is the SRI multiplexing capacityin one subframe/RB and it's possible values are defined in previousdescriptions.

Referring again to FIG. 5, SRI resource indexing 507, 509, 510illustrates indexing per RB across the entire SRI period 512. FIG. 5illustrates the short CP structure with shift separation equal two;however the indexing scheme is similar for other shift separation valuesand for the long CP structure.

PUCCH Level

FIG. 6 is a frequency/time plot illustrating PUCCH and PUSCH,illustrating exemplary resource block indexing. The last multiplexingdimension is the frequency, or RB. Embodiments of the invention pursuethe time indexing, as described above, across all RBs of the PUCCH,starting from RB 602 at the extreme upper end of the PUCCH, asillustrated in FIG. 6, where N_(PUCCH) RBs are allocated to the PUCCH.As a result, the SRI resource indexed by n is located in PUCCH RB #└n/N_(SRI) ^(SFRB)N_(SRI)┘,subframe S0+└(n mod N_(SRI)^(SFRB)N_(SRI))/N_(SRI) ^(SFRB)┘  (16)on the channelization resource indexed by(n mod N_(SRI) ^(SFRB))in Table 4, 6, 8, 12, 14.

The SRI index ordering, described above with reference to Equation (16),is mapped onto physical resources according to a time first, RB(frequency) second ordering. An alternate embodiment can use a frequencyfirst, time second ordering scheme. In yet another embodiment, the SRIindex can only span the channelization indexing addressed with referenceto Tables 2-14 and the frequency RBs of a given subframe, while thesubframe index is configured separately.

SRI Allocation

Whenever an SRI resource has been allocated to an UL synchronized UE, itdoes not need to change since its period is not dependent on varyingconditions such as the radio channel. Moreover an SRI transmission isnot linked to any scheduled allocation conveyed on the PDCCH. As aresult, the SRI index allocation to a UE may be done through L3signaling embedded in a MAC (media access control) PDU (protocol dataunit) on PDSCH. It should be noted that the SRI index as defined hereinspans the whole PUCCH region. This is obviously over-provisioning sincethe SRI shares the PUCCH with the ACK/NACK and CQI channels, and inpractice, it is the responsibility of the eNB, when assigning the SRIindexes to the UEs, to choose which RBs/cyclic shifts/codes will beallocated for SRI transmission. So this only results inover-dimensioning the SRI index bit-width. Therefore, in an alternativeembodiment, an eNB may configure and signal a reduced number of PUCCHRBs to be used for SRI transmission. In that case, the same mappingapplies as described in with regard to FIG. 6, except that RB indexingis limited to those PUCCH RBs configured to support SRI transmission.However, this would require an additional SRI parameter to be broadcastas part of the system information which will increase the overhead onSIBs (system information blocks). On the other hand, as alreadymentioned, the SRI index is expected to be sent very infrequently sosome amount of over-dimensioning should not be an issue. Also, reducingthe number of parameters the eNB needs to configure results in a simplerdesign.

SRI Signaling Requirements

From the above Sections, the signaling requirements in support of theSRI can be reduced to:

The SRI cycle period—broadcast as system information

The SRI cycle offset (e.g. with respect to SFN=0)—broadcast as systeminformation

UE-specific SRI resource allocation (SRI index): L3 signaling in MAC PDUon PDSCH

In an alternate embodiment, the SRI channel can be configured asfollows:

The SRI cycle period—broadcast as system information

UE-specific SRI resource allocation (SRI index): L3 signaling in MAC PDUon PDSCH

UE-specific subframe offset, which tells the UE the subframe within theSRI cycle period it has been assigned an SRI channel

UE-specific n_(PUCCH) ⁽¹⁾ index as the SRI resource within the abovesubframe.

n_(PUCCH) ⁽¹⁾ plays the same role as the SRI index n, except that it isrestricted to one sub-frame; the middle term identifying the subframe#is not accounted in equation 16. As a result, the eNB has to signal bothn_(PUCCH) ⁽¹⁾ and the sub-frame offset to the UE, which will necessarilyrequire more bits compared to the case where both time andfrequency/channelization indexes are merged. However, this UE-specificRRC allocation is expected to occur quite infrequently, which shouldcause too much overhead. On the other hand, this approach presents acommon interface with persistent A/N allocations for which the subframeoffset is UE-specific, which makes overall design simpler.

Note it is possible for NodeB to inform each UE the SRI cycle period viahigher layer signaling (i.e. RRC (radio resource control) or L3 (layer 3of the protocol stack)). The SRI cycle period is typically common to allUEs in the systems. It is not precluded that UE-specific SRI cycleperiod is implemented.

In another embodiment, the SRI cycle period and the subframe offset canbe UE-specific parameters conveyed though L3 signaling in MAC PDU onPDSCH, and grouped into a single index, denoted I_(SR), while n_(PUCCH)⁽¹⁾ is also a UE-specific parameter, but configured separately. Table 15below gives an example of mapping of the I_(SR) index onto pre-definedSRI period and subframe offset values.

TABLE 15 UE-specific SRI periodicity and subframe offset configurationSRI subframe SRI configuration Index I_(SR) SRI periodicity (ms) offset0-4 5 I_(SR)  5-14 10 I_(SR) - 5 15-34 20 I_(SR) - 15 35-74 40 I_(SR) -35  75-154 80 I_(SR) - 75 155 OFF N/A

In this disclosure, a L3 signaling in MAC PDU on PDSCH is sometimesdenoted as RRC signaling, or higher layer signaling, or any otherequivalent term.

FIG. 7 is a flow diagram illustrating allocation and transmission of SRIaccording to an embodiment of the present invention. As described above,orthogonal block spreading codes can be applied to multiple users forsimultaneous transmission within the same frequency—time resource. Thisscheme is used for transmission of SRI. When a UE enters a cell, itreceives 706 from the NodeB serving the cell an allocation of a set ofperiodic transmission instances for SRI. It also receives configurationinformation to instruct it as to which channel resources it is to usefor transmission.

Prior to this, the NodeB determines 702 a mapping scheme that will beused to allocate a unique physical resource to UE within the cell(s)controlled by the NodeB for transmission of SRI. Typically, this will bedone when the NodeB is installed or when the network is laterreconfigured or the cell size changed and will generally depend on thephysical size and location of the cells served by the NodeB. Asdiscussed above, the mapping scheme depends on the type of CP selected,the cyclic shift separation that will be used within the cell,orthogonal covering sequences, and the number of RB that will beallocated for SRI use. Once these details are decided, UE that operatein the network are configured accordingly so that each UE is aware ofthe chosen mapping scheme. This may typically be done when the UE isinitialized for use in the network, such as when a cell phone ispurchased. It may also be done later via control messages.

As each UE enters a cell and becomes identified to the NodeB serving thecell, the NodeB will then transmit 704 to the UE a set of parametersthat allow the UE to determine a unique combination of cyclic shift, RSorthogonal cover, data orthogonal cover, and resource block number forthe first UE to use as a unique physical resource for an SRI in thephysical uplink control channel (PUCCH). This includes transmitting anSRI cycle period for use by user equipment (UE) within a cell,transmitting a specific SRI subframe offset to a particular UE, andtransmitting an index value to the particular UE. The SRI cycle periodis common to all UE within a cell, so this parameter may be broadcast toall UE within the cell, or it may be transmitted specifically to each UEas it enters the cell. For example, the NodeB may inform each UE the SRIcycle period via higher layer signaling using RRC or L3. Similarly,since the mapping does not need to change, the NodeB may inform each UEthe specific offset and index parameter values using RRC or L3.

When a UE receives 706 the logical parameters that define the SRIresource to use, it determines 708 a unique combination of cyclic shift,RS orthogonal cover, data orthogonal cover, and resource block numberfor the UE to use as a unique physical resource for an SRI in thephysical uplink control channel (PUCCH). This is done by mapping thereceived parameters to select a unique physical resource using aone-to-one mapping scheme as described above, with respect to FIGS. 3-5.

During a normal course of operation, whenever a given UE has ascheduling request to transmit, it transmits 710 a positive (or ON) SRIaccording to its unique physical resource SRI allocation and receivesfurther resource allocations using the three step procedure describedwith respect to FIG. 2. This is repeated each time the UE has ascheduling request to transmit. An SRI transmission may be made as oftenas each SRI period, which is typically 10 ms.

FIG. 8 is a block diagram of a transmitter structure 800 fortransmitting the coherent structures of FIGS. 3-5. Elements oftransmitter 800 may be implemented as components in a fixed orprogrammable processor by executing instructions stored in memory. Apre-defined set of sequences is defined. The UE generates in frequencydomain a CAZAC-like (e.g. ZC or extended ZC or zero-autocorrelation QPSKcomputer-generated) sequence using base sequence generator 802. A cyclicshift value is selected for each symbol based on the SRI resource index,the OFDM symbol number and the slot number in cyclic shift selectingmodule 804. The base sequence is then shifted by cyclic shifter 806 infrequency domain, i.e. by applying a phase ramp on a symbol by symbolbasis using shift values provided by cyclic shift selection module 804.The exact values that are used to form the SRI shifted sequences aredetermined by the UE by mapping the logical index value and SRI subframeoffset received from a NodeB that is serving the cell in which the UE islocated to a unique combination of cyclic shift, RS orthogonal cover,data orthogonal cover, and resource block number for the first UE to useas a unique physical resource for an SRI in the physical uplink controlchannel (PUCCH).

Referring again to FIGS. 3 and 4, the UE generates three orthogonalcovering sequences 302, 304, 306 or 402, 404, 406, for example, usingorthogonal sequence generator 808. Orthogonal sequence generator 808generates one sequence out of the set of orthogonal sequences based onthe SRI resource index, as described above, for each of the threecovering sequences. The orthogonal covering sequence sample selection810 selects and issues the appropriate sequence sample from the coveringsequence based on the index of the OFDM symbol being currentlygenerated. The cyclic shifted base sequence vector is element-wisecomplex-multiplied by the selected orthogonal covering complex sample incomplex multiplier 812.

The result of the element-wise complex multiplication is then modulatedby multiplying by one in multiplier 814 if an SRI is pending, asindicated by SRI logic 816 or by multiplying by zero if an SRI is notpending. Other embodiments may implement the on-off keying for SRImodulation in other manners, such as by not forming the sequences atall.

The SRI sequences are then mapped onto a designated set of tones(sub-carriers) using Tone Map 854. Additional signals or zero-paddingmay or may not be present. The UE next performs IFFT of the mappedsignal using the IFFT 856 to transform the OFDM signal back to the timedomain. The CP is then formed using a portion of the OFDM signal outputfrom IFFT 856 and appended to the OFDM signal to form the completeSC-OFDM symbol which is output to the transmitter (not shown). Formationof the SC-OFDM symbol is controlled as described above so that both anSRS and an SRI are not formed in the same symbol.

In some embodiments, the inverse Fast Fourier Transform (IFFT) block in856 may be implemented using an Inverse Discrete Fourier Transform(IDFT). In other embodiments, the order of cyclic shifter 806, tone map854 and IFFT 856 may be arranged in various combinations. For example,in one embodiment tone mapping is performed on a selected root sequence,IDFT is then performed on the mapped tones and then a cyclic shift maybe performed. In another embodiment, the cyclic shift is applied in timedomain on a time domain root sequence, then a DFT precoder transformsthe time domain sequence into frequency domain, tone mapping is thenperformed on the cyclically shifted sequence and then an IDFT isperformed on the mapped tones.

In this disclosure, the cyclically shifted or phase ramped CAZAC-likesequence is sometimes denoted as cyclic shifted base sequence, cyclicshifted root sequence, phase ramped base sequence, phase ramped rootsequence, or any other equivalent term.

System Examples

FIG. 9 is a block diagram illustrating an exemplary portion of thenetwork system of FIG. 1. A mobile UE device 901 is in communicationwith an eNB 902 in a cell served by eNB 902. Mobile UE device 901 mayrepresent any of a variety of devices such as a server, a desktopcomputer, a laptop computer, a cellular phone, a Personal DigitalAssistant (PDA), a smart phone or other electronic devices. In someembodiments, UE device 901 communicates with the eNB 902 based on a LTEor E-UTRA protocol. Alternatively, another communication protocol nowknown or later developed may be used.

As shown, UE device 901 comprises a processor 903 coupled to a memory907 and a Transceiver 904. The memory 907 stores (software) applications905 for execution by the processor 903. The applications 905 couldcomprise any known or future application useful for individuals ororganizations. As an example, such applications 905 could be categorizedas operating systems (OS), device drivers, databases, multimedia tools,presentation tools, Internet browsers, e-mailers, Voice-Over-InternetProtocol (VoIP) tools, file browsers, firewalls, instant messaging,finance tools, games, word processors or other categories. Regardless ofthe exact nature of the applications 905, at least some of theapplications 905 may direct UE 901 to periodically or continuouslytransmit uplink signals via PUCCH and PUSCH to eNB (base-station) 902via transceiver 904.

Transceiver 904 includes uplink logic which may be implemented byexecution of instructions that control the operation of the transceiver.Some of these instructions may be stored in memory 907 and executed whenneeded. As would be understood by one of skill in the art, thecomponents of the Uplink Logic may involve the physical (PHY) layerand/or the Media Access Control (MAC) layer of the transceiver 904.Transceiver 904 includes one or more receivers 920 and one or moretransmitters 922.

The transmitter(s) may be embodied as described with respect to FIG. 8for transmission of SC-OFDM SRI subframes. In particular, as describedabove, a the specific SRI subframe offset and the index value receivedfrom eNB 902 enable UE 901 to determine a unique combination of cyclicshift, RS orthogonal cover, data orthogonal cover, and resource blocknumber to use as a unique physical resource for an SRI in the physicaluplink control channel (PUCCH). This determination may be made bysoftware executed on process 903 using mapping tables or equationsstored in memory 907. Buffer logic 921 coupled to transmitter 922 storesany pending scheduling request. Receiver 920 is operable to receive andstore in memory 907 an allocation comprising a plurality of periodictransmission instances for a scheduling request indicator (SRI) and alogical index value that is used by the UE to map to a unique physicalresource for SRI transmissions, using the methods described above.Buffer logic 921 is controlled by processor 903 and is operable to storea pending scheduling request. Transmitter 922 is responsive to thebuffer logic and is operable to produce and transmit an SRI in atransmission instance allocated for SRI when the buffer logic indicatesthe pending scheduling request.

eNB 902 comprises a Processor 909 coupled to a memory 913 and atransceiver 910. Memory 913 stores applications 908 for execution by theprocessor 909. The applications 908 could comprise any known or futureapplication useful for managing wireless communications. At least someof the applications 908 may direct the base-station to managetransmissions to or from user device 901.

Transceiver 910 comprises an uplink resource manager which enables eNB902 to selectively allocate uplink PUSCH resources to the user device901. As would be understood by one of skill in the art, the componentsof the uplink resource manager 912 may involve the physical (PHY) layerand/or the Media Access Control (MAC) layer of the transceiver 910.Transceiver 910 includes a Receiver 911 for receiving transmissions fromvarious UE within range of the eNB and transmitter 914 for transmissionto the various UE within range. The uplink resource manager executesinstructions that control the operation of transceiver 910. Some ofthese instructions may be located in memory 913 and executed whenneeded. The resource manager controls the transmission resourcesallocated to each UE that is being served by eNB 902 and broadcastscontrol information via the physical downlink control channel PDCCH andthe physical downlink shared channel PDSCH.

A typical eNB will have multiple sets of receivers and transmitterswhich operate generally as described herein to support hundreds orthousand of UE within a given cell. Each transmitter may be embodiedgenerally by a processor 909 that executes instructions from memory 913to perform the scrambling, mapping, and OFDM signal formation, usingsignal processing techniques as are generally known in the art.

In particular, eNB is operable to transmit an SRI cycle period for useby user equipment (UE), including UE 901, within a cell served by eNB902. It transmits a specific SRI subframe offset to UE 901 when itdetects the presence of UE 901 and transmits an index value to UE 901for use in determining a unique physical resource for SRI transmission.The index value corresponds to a one-to-one mapping scheme as describedabove.

FIG. 10 is a block diagram of mobile cellular phone 1000 for use in thenetwork of FIG. 1. Digital baseband (DBB) unit 1002 can include adigital processing processor system (DSP) that includes embedded memoryand security features. Stimulus Processing (SP) unit 1004 receives avoice data stream from handset microphone 1013 a and sends a voice datastream to handset mono speaker 1013 b. SP unit 1004 also receives avoice data stream from microphone 1014 a and sends a voice data streamto mono headset 1014 b. Usually, SP and DBB are separate ICs. In mostembodiments, SP does not embed a programmable processor core, butperforms processing based on configuration of audio paths, filters,gains, etc being setup by software running on the DBB. In an alternateembodiment, SP processing is performed on the same processor thatperforms DBB processing. In another embodiment, a separate DSP or othertype of processor performs SP processing.

RF transceiver 1006 includes a receiver for receiving a stream of codeddata frames and commands from a cellular base station via antenna 1007and a transmitter for transmitting a stream of coded data frames to thecellular base station via antenna 1007. Transmission of the PUSCH datais performed by the transceiver using the PUSCH resources designated bythe serving eNB. In some embodiments, frequency hopping may be impliedby using two or more bands as commanded by the serving eNB. In thisembodiment, a single transceiver can support multi-standard operation(such as EUTRA and other standards) but other embodiments may usemultiple transceivers for different transmission standards. Otherembodiments may have transceivers for a later developed transmissionstandard with appropriate configuration. RF transceiver 1006 isconnected to DBB 1002 which provides processing of the frames of encodeddata being received and transmitted by the mobile UE unite 1000.

The EUTRA defines SC-FDMA (via DFT-spread OFDMA) as the uplinkmodulation. The basic SC-FDMA DSP radio can include discrete Fouriertransform (DFT), resource (i.e. tone) mapping, and IFFT (fastimplementation of IDFT) to form a data stream for transmission. Toreceive the data stream from the received signal, the SC-FDMA radio caninclude DFT, resource de-mapping and IFFT. The operations of DFT, IFFTand resource mapping/de-mapping may be performed by instructions storedin memory 1012 and executed by DBB 1002 in response to signals receivedby transceiver 1006.

For SRI transmission, a transmitter(s) may be embodied as described withrespect to FIG. 8 by executing signal processing code in DBB 1002. Inparticular, as described above, a receiver within transceiver 1006receives an SRI cycle period for use by user equipment (UE) within acell, a specific SRI subframe offset, and an index value upon entering acell. An application program executed by DBB 1002 then uses the specificSRI subframe offset and the index value to determine a uniquecombination of cyclic shift, RS orthogonal cover, data orthogonal cover,and resource block number to use as a unique physical resource for anSRI in the physical uplink control channel (PUCCH). Parametersidentifying this unique physical resource may then be stored in DBB 1002for use by the transmitter.

DBB unit 1002 may send or receive data to various devices connected touniversal serial bus (USB) port 1026. DBB 1002 can be connected tosubscriber identity module (SIM) card 1010 and stores and retrievesinformation used for making calls via the cellular system. DBB 1002 canalso connected to memory 1012 that augments the onboard memory and isused for various processing needs. DBB 1002 can be connected toBluetooth baseband unit 1030 for wireless connection to a microphone1032 a and headset 1032 b for sending and receiving voice data. DBB 1002can also be connected to display 1020 and can send information to it forinteraction with a user of the mobile UE 1000 during a call process.Display 1020 may also display pictures received from the network, from alocal camera 1026, or from other sources such as USB 1026. DBB 1002 mayalso send a video stream to display 1020 that is received from varioussources such as the cellular network via RF transceiver 1006 or camera1026. DBB 1002 may also send a video stream to an external video displayunit via encoder 1022 over composite output terminal 1024. Encoder unit1022 can provide encoding according to PAL/SECAM/NTSC video standards.

Other Embodiments

While the invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various other embodiments of the invention will beapparent to persons skilled in the art upon reference to thisdescription. For example, a larger or smaller number of symbols thendescribed herein may be used in a slot.

In some embodiments, a transmission instance may refer to a subframethat contains two slots as describe herein. In another embodiment, atransmission instance may refer to a single slot. In yet otherembodiments, a transmission instance may refer to another agreed uponlogical time duration that may be allocated for transmission resources.

As used herein, the terms “applied,” “coupled,” “connected,” and“connection” mean electrically connected, including where additionalelements may be in the electrical connection path. “Associated” means acontrolling relationship, such as a memory resource that is controlledby an associated port.

It is therefore contemplated that the appended claims will cover anysuch modifications of the embodiments as fall within the true scope andspirit of the invention.

What is claimed is:
 1. A method of transmitting a scheduling requestindicator (SRI) comprising: receiving an SRI configuration index I_(SR)from a user equipment (UE) for use by a base station within a cell;determining an SRI periodicity SRI_(periodicity) and a SRI subframeoffset SRI_(subframe) offset from the SRI configuration index ISR foruse by user equipment (UE)within a cell; transmitting the SRIperiodicity SRI_(periodicity) and the SRI subframe offset SRlsubframefor use by user equipment (UE) within a cell; wherein the SRI istransmitted on a two-state SR channel.
 2. The method of claim 1 whereinthe SRI configuration index I_(SR) is transmitted in level three (L3)signaling in media access control (MAC) protocol data unit (PDU) on aphysical downlink shared channel (PDSCH).
 3. A device for transmitting ascheduling request indicator (SRI) comprising: a processor operable toexecute instructions, coupled to a memory containing instructions forthe processor; a radio receiver and a transmitter coupled to theprocessor; wherein the receiver is operable to: receive an SRIconfiguration index I_(SR) from a user equipment (UE) to a node; whereinthe processor is operable to: determinine a SRI periodicitySRI_(periodicity) and a SRI subframe offset SRI_(subframe offset) fromthe SRI configuration index I_(SR); wherein the transmitter is operableto: transmit the SRI periodicity SRI_(periodicity) and the SRI subframeoffset SRI_(subframe); wherein the SRI is transmitted on a two-state SRchannel.
 4. The device of claim 3 wherein the SRI configuration indexISR is transmitted in level three (L3) signaling in media access control(MAC) protocol data unit (PDU) on a physical downlink shared channel(PDSCH).